Is "to" missing in the following phrase: "civil liberties be damned"?

It is equivalent to "Let civil liberties be damned"

Although Martin's answer is correct, the meaning is indeed equivalent to let…, it fails to explain the actual grammar behind.

civil liberties be damned.

This sentence uses subjunctive mood. It can be recognized because verbs in subjunctive present use the bare infinitive for all persons. For most verbs it makes no difference but for the 3rd person. For to be, however, it becomes in subjunctive present: I be, you be, he/she/it be, we be, they be.

It is this construction that gives “so be it” or “God save the Queen” (notice the lack of a s on save). Or “civil liberties be damned”.

There are several uses for subjunctive, involving wish-like verbs (“I wish he come” - correct albeit not used much those days). But it is also possible to use it standalone. In this case, Wikipedia says “a present subjunctive verb form is sometimes found in a main clause, with the force of a wish.”